To transmit trigger signals, contact switches become popular in application as discrete devices for coupling to electrical signals. Contact switches are classified as rocker switches and pushbutton switches. Commonly, a pushbutton switch has an elastic part and a connector coupled to a circuit. On the basis of the states (on or off) of the elastic part with respect to the connector, the switch function is implemented.
On the other hand, in order for a user to assure if a contact switch is on, an indicator is installed in the switch, showing the on or off state of the switch. However, the current contact switches take large space with complicated structures at high costs since in each of these switches, the indicator and the switch are discretely installed.
U.S. Pat. No. 6,621,025 to Yei et al., (“Yei” hereinafter) entitled “Rocker Switch with LED Indicators” proposed a switch assembly that comprise a base having two pairs of L-shaped members received therein and each of the L-shaped members has a spring connected thereon. Two V-shaped members are respectively located between the two pairs of L-shaped members. A frame is mounted on the base and has an open top. A flange extends from an inside of the open top and has four apertures defined there through. A circuit board is supported on the flange in the frame and two LEDs are connected on the circuit board.
Four bosses extend from an underside of the circuit board and contact the spring via the apertures in the flange. A cap is engaged with the open top of the frame and two holes are defined through the cap so that the LEDs are engaged with the holes. An activation member extends through the circuit board and a shaft of the activation member extends through the cap. Two extensions of the activation member contact the V-shaped members. A see-saw switch is connected to the shaft of the activation member.
While the switch proposed by Yei combines LEDs with a switch to render an assembly taking small space and a lot fewer parts, its structure is still quite complicated and manufacture costs are high. In addition, the Yei's switch works by tilting the see-saw switch at right end or left end, so this structure is only applied to rocker switches, not to pushbutton switches.
Current pushbutton used for electrical products functions as a switch. When an on or off state is to be displayed, an extra circuit for controlling a LED is required. Furthermore, a receipt hole has to be made on the panel of the electrical product to accommodate the LED indicator, taking much space.
U.S. Pat. No. 6,040,534 to Beukema (“Beukema” hereinafter) discloses an integrally molded switch lighting and electronics, including a cover 70 with translucent indicia 84 directly above phosphorous electro luminescent pad 67, as shown in FIG. 1. Beukema's arrangement uses the resilience of the polycarbonate cover 70 to bias the return of the switch in a cantilever-like arrangement. While Beukema integrates the display part and the switch, it does not save space. Also, since this switch is used on a flexible circuit, it makes the manufacture complicated.
Chinese Utility Model Patent No. CN 2433724Y (“CN Patent” hereinafter) taught an improved pushbutton switch including a upper shell, a pushbutton pole, a spring, and a lower shell. On the upper shell are arranged an accommodation room, two hole, a “□” control pole and a plurality of tenon slots. The pushbutton pole is of a control track and a groove for the use of two connectors. On the lower shell are a LED, a base trough for setting up the LED, a tenon slot for coupling to the upper shell. By pressing the switch, the circuit is connected and through the LED imbedded in the pushbutton switch, the on or off state is displayed. This patent also exists the problems of needs of many parts and bulk structure. It is hard to be used in portable electrical products and lacks aesthetic feelings.
Accordingly, what is needed is a switch assembly of mini size, simple structure, high integration, aesthetic appearance, and low costs. Moreover, the switch assembly may display it on or off state of it.